Detectors for detecting chemical substances are known.
Apparatuses for and methods of performing an analysis of a chemical substance, including an analysis utilizing ion mobility spectrometry (IMS), are known. Often, these apparatuses/methods include parameters which enhance an amount of the chemical substance available for analysis, thus improving the macroscopic sensitivity of the analysis. An increased concentration of substance available for analysis, which can be deposited on a membrane of an ion mobility spectrometer (IMS) system, in turn, increases the macroscopic sensitivity of the analysis by allowing additional sample chemicals to pass through the membrane of an IMS system for analysis, due to the additional amounts of sample transferred to the membrane.
Apparatuses for and methods of performing an analysis of a chemical substance often utilize particle separators to separate particles from a gas (such as air). Cyclones, a type of inertial separator, are commonly used to collect atmospheric particles and the like for sampling purposes or filtering, for example: Incoming gas and particles are subjected to cyclonic motion within the cyclone such that the particles separate from the gas due to the differing densities. More specifically, the particles are forced to the wall of the cyclone, which is typically wetted with a sample collection fluid, such as a buffer solution. The particles contact the sample collection fluid and become suspended in it. The sample collection fluid is then collected, and the particles can be analyzed or disposed of, for example. Exemplary cyclones are described in the following patent document publications: See e.g., U.S. Pat. No. 5,918,259, U.S. Pat. No. 6,508,864, Japanese Patent Pub. No. 63-224754, German Patent Pub. No. 2004808, Switzerland Patent Pub. No. 251108, and International Patent Pub. No. WO 2004/065017. As can be seen from these documents, exemplary cyclones can have outlets provided by a tapering, funnel-shape continuation of the inside surface of the cyclone such that the mixture flows internally off the funnel-shape surface.
Cyclones have several limitations. For example, not all of the particles that enter the cyclone are collected. Sample can be aerosolized resulting in loss of sample stored inside the cyclone. Loss of sample reduces particle collection efficiency and requires additional fluid to meet the desired outlet flow rate. The need for large amounts of sample collection fluid can be a significant limitation of current cyclones particularly when the cyclone is to be run for long periods of time, and especially where the cyclone will be run continuously and unattended for long periods of time.